1. Field of the Invention
The present invention relates to a socket for automotive vehicles to be exclusively used for appliances having a plug for connecting to the cigarette lighter socket in the automotive vehicle.
2. Description of the Related Art
Hitherto, the socket for cigarette lighters is used for the provided appliances to be use in the automotive vehicle. However, a bimetal to which the heater cap of the plug of the cigarette lighter is fitted is projected from the insulator on the inner wall in such a socket. When a plug of the appliance for automotive vehicle other than the plug of the cigarette lighter is inserted into the socket for cigarette lighters, the plug resists engaging the bimetal described above, whereby the bimetal may disadvantageously be deformed or the plug of the appliance for automotive vehicles may be damaged.
As a socket devised to solve the problem described above, for example, there is a device disclosed in Japanese Utility Model Publication No.22552/1985. This socket is provided with a resinous mounting base on the side of the opening of the metal body, and with an insulating board having a terminal fitting and an insulating base having a terminal on the side of the bottom surface of the body. The body is formed of a conductive body almost in the shape of a can, and comprises a resilient strip to be brought into electrical contact with the plug and the bottom portion to be brought into electrical contact with the earth terminal to construct a part of an electric circuit. The bottom surface of the body is fixed with the terminal fitting, the insulating board, the insulating base, the earth terminal, and the plus terminal by caulking the terminal fitting.
However, since the socket described above is formed of a metal body comprising a resinous mounting base provided on the side of the opening and an insulating board having a terminal fitting and an insulating base having a terminal provided on the side of the bottom surface, the number of the components are large, and thus the number of steps to assemble, thereby increasing the cost.
The socket of the related art has only two holes; an opening and a notch formed by cutting three sides of the square in the vicinity of the opening; and the bottom surface of the socket has no hole thereon. Therefore, there are problems in that the heat releasing effect in case of abnormal heat generation in the plug is small, and in that when the water entered therein, it cannot be discharged easily. In addition, when the body is heated, the heat is easily transmitted to the whole part of the metallic body, and thus the collar of the body outside of the flange may cause burn injury when the body gets into touch with it.
Since the size of the socket and the plug for cigarette lighters varies conventionally, there is recognized problem in that the plug may fall off the socket due to the vibration of the vehicle body when the size of the plug does not conform to the size of the socket.
Accordingly, the object of the present invention is to provide a socket for automotive vehicles in which the number of the parts and the number of steps for assembly are small and the cost is low.
The present invention is directed to solve the problems of the related art described thus far, and the invention according to a first aspect is a socket for automotive vehicles for receiving the plug of the appliance for automotive vehicles to electrically connect to the power supply, comprising a near cylindrical resinous molded body having a flange formed along the outer periphery of the opening to which the plug is inserted, and terminals formed on the bottom surface by insert molding.
The invention according to a second aspect is an invention according to the first aspect, wherein the socket is provided with a conductive inner case to be brought into contact with resilient electrodes of the plug on the inner wall surface of the socket, and a bimetal to be brought into contact with the terminal in conduction with the inner case in case of abnormal heat generation is electrically connected to the terminal disposed on the bottom surface thereof.
The invention according to a third aspect is an invention according to the second aspect, wherein the inner case comprises a cylindrical portion formed on the inner wall surface of the socket, the terminal projected from the cylindrical portion, and the earth terminal all formed of a piece of conductive metal plate.
The invention according to a fourth aspect is an invention according to the third aspect, wherein the terminal and the earth terminal are formed by tucking down from the inner wall surface of the socket to form recesses for disposing the resin material forming the socket.
The invention according to a fifth aspect is an invention according to the second, third or fourth aspect, wherein the terminal comprises a power supply connecting portion projecting outwardly from the bottom surface of the socket for being connected with the power supply, and a connecting projection being in contact with the electrode portion of the plug and exposed from the center of the bottom surface, and wherein the bimetal is electrically connected to the terminal at the portion surrounding the connecting projection.
The invention according to a sixth aspect is an invention according to the fifth aspect, wherein the terminal includes a supporting strip for positioning thereof projecting outwardly from the portion surrounding the connecting projection to be supported by the metal mold when the socket is molded by the metal mold.
The invention according to a seventh aspect is an invention according to the sixth aspect, wherein the bottom surface of the socket is formed of insertion holes adjacent to the supporting strips or the connecting projection.
The invention according to an eighth aspect is an invention according to the fifth aspect, wherein the bimetal is formed into the shape of near L-shape and formed with a through hole for fitting the shoulder formed around the connecting projection therein on one end and provided with a temperature deformation portion inserted into the hollow portion formed on the bottom surface of the socket so as to be opposed to the terminal in conduction with the inner case on the other side.
The invention according to a ninth aspect is an invention according to the first, second, third, fourth, fifth, sixth, seventh or eighth aspect, wherein the socket includes a projection formed of an insulating resin on the bottom surface.
The invention according to a tenth aspect is an invention according to the first or second aspect, wherein the socket is formed with a resilient arresting strips on the outer periphery thereof to which the inner edge of the mounting hole on the vehicle-side member abuts, and a threaded portion with which the nut for screwing the socket to the mounting hole on the vehicle-side member engages.
The invention according to an eleventh aspect is an invention according to the first, second, third, fourth or tenth aspect, wherein the socket is formed in the opening with a plug holding portion to which the resilient supporting portions provided on the outer periphery of the plug engages.
The invention according to a twelfth aspect is an invention according to the eleventh aspect, wherein the socket is provided with a mark on the flange for registering the resilient supporting portion of the plug and the plug holding portion.